It is one thing to say that the suffering of non-human animals ought to be considered equally with the like suffering of humans; quite another to decide how the wrongness of killing non-human animals compares with the wrongness of killing human beings. It is argued that while species makes no difference to the wrongness of killing, the possession of certain capacities, in particular the capacity to see oneself as a distinct entity with a future, does. It is claimed, however, that this is not the only factor to be taken into account: pleasant or happy life is in itself good. The application of these conclusions to killing animals for food is then considered, with some passing reflections on infanticide.